.error {
    border: 1px solid red;
    background-color: #fdd;
}
.seriousError {
    @extend .error;
    border-width: 3px;
}

.error a {
    color: red;
    font-weight: 100;
}
h1.error {
    font-size: 1,2rem;
}

.test {
    color: red;
    @extend .succ;
}
h1.succ {
    font-size: 12px;
}